How to add math in PHP echo? - php

Question

I have a website that everything is working well except lowest price. I mean all prices will be changed based on selected currency but not lowest price.
Lowest Price is showing correctly just based on US dollar not other currencies, I mean If we will change currency to Euro, still lowest price is showing on US dollar which is default currency.
In my Sql Database I have a table pt_currencie and Column rate
and on my room page, lowest price is showing with following PHP code:
<?php echo $lowestPrice; ?>
and in the controller, the code is:
$this->data['lowestPrice'] = $this->hotels_lib->bestPrice($this->data['hotel']->id);
and here is setting for userdata and change currency
function changeCurrency($id){
$this->db->where('id',$id);
$rs = $this->db->get('pt_currencies')->result();
$this->session->set_userdata('currencycode', $rs[0]->code);
$this->session->set_userdata('currencysymbol', $rs[0]->symbol);
$this->session->set_userdata('currencyname', $rs[0]->name);
$this->session->set_userdata('currencyrate', $rs[0]->rate);
}
}
How can I show $lowestPrice based on selected currency (rate) ?
what formula should I add into above code that lowest price show based on selected currency?

Answer 1

Ok if I'm understanding your question correctly, you will have to take the currency rates out of the db into a php array and then determine the lowest price using php with something like this:
$query = "SELECT rate FROM pt_currencie";
$result = mysqli_query($db_conn, $query);
$rate_arr = mysqli_fetch_fields($result);
$currLowestPrice = $lowestPrice;
foreach ($rate_arr as $rate) {
$tmpLowestPrice = $lowestPrice * $rate;
if($currlowestPrice > $tmpLowestPrice)
$currLowestPrice = $tmpLowestPrice;
}
So this should atleast give you the lowest price in $currLowestPrice for adjusted to currency rates by the end of the for loop (the code above will probably have to be adjusted a bit for your program)